BMW I01, Информация о продукте

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I01�High-voltage�Components
8.�Electric�Heating
141
Index Explanation
15 Electronic�switch�(Power�MOSFET)�for�heater�coil�3
16 Heater�coil�1
17 Heater�coil�2
18 Heater�coil�3
The�current�through�the�individual�strands�is�measured�and�controlled�by�the�electric�heating�control
unit.�A�current�of�maximum�20�A�flows�in�a�voltage�range�of�250 V�to�400 V.�The�power�is�reduced
above�and�below�this�voltage�range.�At�increased�power�consumption�the�energy�supply�by�the
hardware�switching�is�interrupted.�This�switching�is�designed�so�that�even�in�the�event�of�a�fault�in�the
control�unit�a�power�cut�is�effected�safely.
The�temperature�of�the�coolant�is�measured�using�a�sensor�at�the�output�of�the�electric�heating.
Inside�the�electric�heating�a�galvanic�separation�was�installed�between�the�high-voltage�circuit�and�the
low-voltage�circuit.
The�connections�for�local�interconnect�network�bus�and�voltage�supply�(terminal�30B)�are�located�at
the�low-voltage�connector.
A�bridge�is�integrated�in�the�high-voltage�connector�beside�the�contacts�for�the�high�voltage.�The
contacts�of�the�bridge�in�the�high-voltage�connector�are�designed�as�leading�contacts.�This�means
when�removing�the�high-voltage�connector�the�contacts�of�the�high-voltage�bridge�are�separated�first.
As�a�result,�the�voltage�supply�of�the�control�unit�(EH)�is�interrupted.�This�also�means�the�high-voltage
supply�is�interrupted�before�the�high-voltage�connector�is�pulled�out�fully.�No�electric�arc�thus�arises
on�the�high-voltage�contacts.�The�high-voltage�contacts�are�protected�from�contact.�The�high-voltage
connector�of�the�electric�heating�is� not �part�of�the�circuit�of�the�high-voltage�interlock�loop.
8.3.�Control�system
Six�heating�stages�can�be�set�through�separate�or�combined�activation�of�the�individual�heater�coils.
The�request�for�switching�on�the�heating�comes�from�the�IHKA�control�unit�via�local�interconnect
network�bus.
Heater�coil Heating�stage
1 1
2 2
3 3
1�+�3 4
2�+�3 5
1�+�2�+�3 6
When�the�maximum�temperature�is�reached�or�if�the�maximum�permissible�current�level�is�exceeded,
the�heater�output�is�automatically�restricted�by�the�electric�heating�control�unit.
The�electric�heating�is�switched�off�in�the�event�of�system�faults.
The�electric�heating�is�maintenance-free.